Doctoral Dissertation Research: Modern Pollen Spectra from Coasts and Lowlands of the Dominican Republic and Their Application to the Interpretation of Sedimentary Pollen Records

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This doctoral dissertation research project will examine whether neotropical lowland and coastal vegetation is represented by unique assemblages of pollen taxa through analysis of modern pollen from surface soils and sediments. While reconstructions of past vegetation, climate, and environment have been successfully derived from tropical sedimentary records, the lack of modern pollen records has limited knowledge about pollen-vegetation relationships and restricted the interpretation of tropical sedimentary pollen. Several modern pollen studies have been conducted in mainland tropical America, but few studies have been conducted on Caribbean islands. Furthermore, of the modern pollen studies examining tropical dry or seasonal vegetation types, few have examined spectra from mature lowland seasonally-dry forests. This doctoral dissertation research project will focus on the modern pollen spectra of lowland and coastal Dominican Republic, which includes sites in seasonally-dry forests. The doctoral student and colleagues will collect modern pollen samples from a variety of vegetation types, including grasslands, sedge wetlands, mangroves, coastal scrubs, lowland seasonally dry forests, moist lowland semi-deciduous forests, and humid forests. The samples will be processed using standard techniques with pollen and spores counted via light microscopy. Discriminant analysis will be used to classify pollen data into groups representing vegetation types and allow the generation of a predictive model. This model then will be applied to the interpretation of fossil pollen assemblages from previously collected sediment cores (and future ones) in the southwestern Dominican Republic. This project will be the first study of modern pollen spectra from coastal and lowland vegetation in the Greater Antilles. It will contribute to knowledge about Caribbean vegetation types, including the floristic composition and diversity of seasonally-dry tropical forests, which are rapidly disappearing from the Caribbean region. This project will strengthen the interpretation of sedimentary pollen records from lowland and coastal lakes on Hispaniola and throughout the Caribbean, thus providing improved understanding of Caribbean vegetation and climate dynamics across long time scales. Project results will assist in the preservation of natural resources of the Dominican Republic. Modern pollen data and metadata will be submitted to the Latin American Pollen Database, a collection of free-to-download fossil and modern pollen data, thereby facilitating future research by other researchers. As a Doctoral Dissertation Research Improvement award, this project will provide support to enable a promising student to establish an independent research career